1970 Oldsmobile Delta 88
2dr Holiday Coupe
8-cyl. 350cid/310hp 4bbl
With an experienced team and a lot of data.
The Oldsmobile 88 was offered in some form from 1949 through the 1999 model year. Over its 50-year run, the 88 had a whole library full of interesting model names, but the car was always an 88. In the 1950s and 1960s, the 88 was Olds’ top seller.
For 1965, the Oldsmobile 88 series was available in three jaunty trim levels, known as the Jetstar 88, Dynamic 88, and the Delta 88. The Dynamic line was the base model, and the Delta added mostly chrome trim as well as some creature comforts such as a center armrest and courtesy lights. Available body styles included the attractive two- or four-door Holiday hardtop, four-door “Celebrity Sedan,” or a two-door convertible.
The Jetstar 88 received the Starfire 330-cid V-8 at 260 hp, but the optional JetStar I line received the 425-cid V-8 at 370 hp. All 1965 Dynamic and Delta 88 models received a 425-cid Super Rocket V-8 engine. The base 425 offered 300 hp, though optional carburetion could boost that number as high as 370 hp, too. A three-speed column-shifted manual transmission was standard, with optional floor-mounted three- or four-speed, or an optional Turbo-Hydramatic.
The 1966 model year was the last for the Jetstar, and the first for the Delta 88 as a separate model. Meanwhile, the Dynamic 88 continued on mostly unphased. While the Delta 88 went upscale, offering more luxury features, the Dynamic 88 remained the mid-grade trim level. Convertibles were available only in Dynamic and Delta trims. Body changes were minor, and engine/drivetrain options remained fundamentally the same.
The 1967 model year was bigger for changes, as the 88 line got a facelift to keep pace with the times. Gone were the straight lines of the middle 1960s, replaced by more sweeping styles in the GM “coke bottle” design language of the era. Trim level names changed, with the creative “Delmont” as the entry-level 88. The Delta 88 remained the top trim level, but it was divided into the standard Delta 88 and the upscale Delta 88 Custom. The Custom line was available only in two- or four-door hardtop styles. The 1967 Delmont 88s also carried an engine designation of 330 or 425 – referring to the size of the engine in the car. Convertibles were offered only with the 425-cid engine. The 330-cid V-8 offered 250 hp, while the 425 delivered 300 hp.
Only minor changes were instituted for 1968, with the 330 engine growing to 350 cid and no power gain. The 425 engine grew to 455 cid and 310 hp, gaining 10 over the prior year.
For 1969 and 1970, the short-lived Delmont was abandoned, and all 88 models would be considered Delta 88s. Three trim levels were now offered in the Delta 88 line – a base level, then Custom, and finally the Royale level at the high end. Royales received custom paint, a vinyl roof, and an electric clock. The Royale was available only as a two-door Holiday Hardtop coupe. Engines were unchanged, but wide and close ratio four-speed manual transmission options were available in 1969.
As with all domestics in this era, enthusiasts will want to look for convertibles and hardtops with the most powerful engine offered for the particular year and model. Dynamic 88s from 1965 and 1966 stand the test of time best with their classic mid-60s lines. Very few four-speed manuals were ever built, so an 88 with that option would be rare indeed.